Back to the books for many children School: Though summer hasn't faded, classes start in several counties this week. The pre-Labor Day openings will let students finish school by mid-June.

By mid-morning Saturday, Kate Lally had a new haircut and was busily working her way down her shopping list. But she couldn't wait to finish her errands. She wanted to get to the pool.

After all, it was her last free weekend of summer.

Today, the 10-year-old goes back to elementary school in Columbia. Back to setting an alarm clock. Back to math tests. Back to homework assignments.

For children in Howard and Carroll counties, classes start early this year. Both public school systems open this morning -- a week before most other schools in Maryland, and two weeks before Labor Day, which used to mark the traditional end of summer vacation.

"It does seem early," said Liz Perraud, 38, while shopping for school supplies with her 10-year-old son, Stephen, who attends Atholton Elementary School with Kate. "We're not ready yet for the end of summer."

Over the past 25 years, more public schools have begun to open the week before Labor Day, instead of the day after the holiday.

The 180-day school calendar, with an extended summer break, is a holdover from the country's rural past. Few people want to change the standard school year, though few children spend their summers working on family farms.

Many school systems prefer to let children out earlier in June, and in exchange want them to return in late August instead of September. This year, the Carroll and Howard schools chose to open earlier to compensate for four days that will be lost this fall -- two to religious holidays and two to elections.

With Labor Day later, some parents wonder if the schools could not have waited a little longer. They fear the children will be unable to concentrate in classes without air conditioning, and some schools could send them home early because of the heat.

Each of Maryland's 24 school systems devises its own calendar. Howard and Carroll schools reopen first this week, with Baltimore County following Wednesday. Public schools in the city and in Anne Arundel, Prince George's and Montgomery counties start Aug. 31. By the Tuesday after Labor Day, all 838,500 children enrolled in Maryland public schools will be back in class.

Harford County is one of the last holdouts. With Wicomico and Worcester counties on the Eastern Shore, Harford decided to wait to start school until Sept. 8, the day after Labor Day.

Harford school officials considered opening five days sooner. They relented after farmers complained that their children would be forced to choose between classes or participating in 4-H events at the Maryland State Fair.

Until four years ago, Carroll County also resisted starting classes before Labor Day in deference to its rural heritage and the state fair. In 1994, the increasingly suburbanized county made the switch because more parents and teachers seemed worried about getting out late in June.

School board member Ann Ballard said a few farm parents protested. But she advised a 4-H mother that the trade-off would be no more popular. "I told her we'd be going to school almost until the Fourth of July if we did that," she said.

The Carroll school staff originally proposed a calendar beginning Aug. 31, but students would not have gotten out of school until June 17. That schedule didn't sit well with board members and parents, who felt that the pre-Labor Day start was to avoid ending school late.

Another timing problem was created by the two fall election days -- the Sept. 15 primary and Nov. 3 general election -- when schools are closed.

Howard County made the same decision because of the election and two Jewish holidays, said school spokeswoman Patti nTC Caplan.

Howard schools opened Aug. 25 last year, but Labor Day was earlier. To Heidi Gonzales, whose 5-year-old son is entering kindergarten at Columbia's Guilford Elementary, this year's start seems to "cut summer short."

"It's still hot," she said, "and Labor Day is still ahead, and that was always a special time in my family, where we all got together for a picnic. I grew up in Baltimore, and I'm still not used to the idea of going to school this early."

The Baltimore County school board has compromised in an attempt to keep the first day of classes close to Labor Day.

If Labor Day falls on or before Sept. 4, the first day of school would be the next day. If Labor Day is later, classes start the week before the holiday.

Under the new policy, Baltimore County will have a post-Labor Day start again in the 2000-2001 school year. As in Howard and Carroll, Baltimore County schools are opening this week to be finished by mid-June.

Sharon Norman, the school system's director of business and community relations, acknowledged getting a few complaints about the Aug. 26 start. But she points out that most celebrated last June when the mild winter permitted an early closing.

"Schools were done June 5 and we didn't hear a single complaint," Norman said. "The only way we get the chance to end the school year that early is if schools begin in August."